The poly[2-(9',9'-bishexylfluorenyl)-1,4- phenylenevinylene] (BHF-PPV), which is PPV containing 9,9- bishexylfluorene as a pendant group, was synthesized by the modified Gilch dehydrohalogenation polymerization of the corresponding bischloromethyl-substituted benzene monomer. The energy levels of the highest occupied molecular orbital and the lowest unoccupied molecular orbital of BHF-PPV were 5.35 and 2.94 eV as determined by cyclic voltammetry. Band gap, estimated from both cyclic voltammetry and optical absorption measurement, agrees well to be 2.41 eV. The EL spectrum showed two peaks at 504 and 535 nm, which very closely resembled the PL spectrum of the polymer film, demonstrating that the PL and EL originate from the same excited state. Blue-green LED was fabricated using BHF-PPV as the emissive layer, PEDOT:PSS as the hole-injection layer, and Mg-Ag alloy as the cathode. The device emitted bright blue-green light with turn-on voltage of 3.0 V and exhibited luminance efficiency and power efficiency of 0.64 cd/A and 0.45 lm/W, respectively, at the luminance of 105.1 cd/m2 driven at the voltage of 4.5 V and current density of 16.37 mA/cm2.